The present invention relates to an identification unit and an identification method of an article.
For example, the present invention relates to a card for which money is paid beforehand and where information and functions of quantity equivalent to the paid money are coded and recorded, such as a so-called prepaid card or a digital cash card which is a type of an IC card via which money can be received and paid, Further, the present invention relates to a cash card and a credit card wherein equivalent money is withdrawn from its owner""s account for a purchased article An identification system is adopted to check that a user of a card is its owner. That is, the above system includes a system of registering personal identification numbers in a card beforehand and checking whether input numbers are equal to the registered personal identification numbers or not when using the card. For such identification of a card, technology for preventing duplication and unfair use has been developed and there are well-known examples of such technology.
It is disclosed in Japanese patent laid open Hei 08-211215 to prevent duplication and forgery by utilizing etching technology in the manufacture of a semiconductor device and by using an optical diffraction structure in relation to a credit card, an identification card and others. In the above well-known example, an identification label composed of a diffraction structure formed on a substrate based upon artificial data and further, a transparent overcoat layer on the diffraction structure is disclosed. For a well-known invention using a crack for identification information, there is known U.S. Pat. No. 4,661,983.
Also, for a personal identification method and a personal identification unit in a security system for identifying a user of a card as its owner, another well-known invention uses organism information such as a finger print pattern, an iris pattern, a blood vessel pattern of an eye and a capillary vessel pattern is known. For example, a unit utilizing a finger print is disclosed in Japanese patent laid open Sho 63-123168. Further, a well-known invention utilizing a radioscopic image of a blood vessel for personal identification information is disclosed in Japanese patent laid open Hei 07-21373.
In the meantime, for a method of managing a wafer in a semiconductor device manufacturing process, a method of marking a character and a number respectively having irregularities on the surface by a laser beam and a focused ion beam (FIB) as a mark for recognition on a wafer is disclosed in Japanese patent laid open Hei 08-31705.
At present, there is technology that prevents the decoding of an ID of an IC card, duplication of an IC card and unfair use thereof as described above. In the meantime, it is also a fact that such unauthorized uses of IC cards have not been completely prevented by the current technology.
In the present invention, an article is provided with identification information for making unfair duplication and use of an unfairly duplicated article extremely difficult, and an identification unit and an identification method respectively utilizing the above identification information of the article are provided. The present invention uses a crystal defect as identification information which is extremely difficult to compose artificially.